While we are talking about Kurzgesagt: https://youtube.com/watch?v=HjHMoNGqQTI

I got sucked into spending quite a while reading about that stuff after seeing a link to Gold on HN. He was an interesting guy. Since he died in 2004 some of his ideas, like a lot of life in the crust seem to have proven correct. Others - that most oil and gas has a primordial origin, not from life seem mostly wrong. There are definitely primordial hydrocarbons - Titan has seas of methane. However on the inner planets a lot evaporated and the majority of our fossil fuels seem of biological origin.

There's a maybe better (very good) article on life in the crust from the NYT june 2024 here https://www.nytimes.com/2024/06/24/magazine/earth-geomicrobi... . Top comment "This article is one of the most powerful articles I have ever read in the NYT. I am so grateful that the author wrote it. It cemented my belief that that all life is deeply connected from the beginning to the present day and beyond..."

Here's a survey article from the late 80s which should have a rich references section for you:

Ghiorse & Wilson, https://doi.org/10.1016/S0065-2164(08)70206-5

I think there are two strands: petroleum companies have long been interested in any connection between deep biology and oil; and I think around that time people found microbes in a few sterile-seeming aquifers.

There are areas on Mars where we strongly believe brine is right below the surface, so there could be life underground but it may not all be that deep.

Edit: found it:

https://www.jpl.nasa.gov/images/pia10911-ice-on-mars-now-its...

There have been cases where we believe we've seen ice form in rover tracks, hinting at water just below the surface.

clarke's "the fires within" was coincidentally also published in 1947

Every time we assume a limitation like this we've been wrong. If tardigrades can survive floating through space, I think it's reasonable to guess that there might be life that survives at the other extreme.

> 180C at that depth. That's well beyond what even the most durable hyperthermophile organisms can withstand

How about the organisms living in or around the hydrothermal vents in the mid-ocean ridges?

There's loads of life down there but there seems a top limit to all known life around 130C. "The current record growth temperature is 122 °C, for Methanopyrus kandleri".That allows you to go ~10km down.

Seems a lot more productive and straightforward to sample rather than speculate.

1 cross borehole electromagnetic imaging rhubarb

We can pretty clearly delineate how much of warming and CO2 concentration is human-caused.

That's clearly what they mean by "how its supposed to be". Yes there's no true "how it's supposed to be" but there's no use in being pedantic when we all clearly understand what they're talking about.

Human accelerated change is the concern.

Some comics [0] [1] might be able to get the point across in a way that words seldom do when arguing on the interblags.

You're right to call out that we don't know the "ideal" state of anything. I, for one, am excited about higher mean rainfall, more exotic weather patterns, and the changes in flora and fauna we expect to see as a result. Many species we currently know and love (e.g., basically everything interesting off the west coast of the US or north coast of Australia) will likely be exterminated, but the world will adapt just fine to those new evolutionary pressures. We don't have enough carbon available to create a Venus scenario, so the worst-case probably doesn't kill off all life, and a little chaos can be exciting. I'm sure other people have more sane lists of pros to weigh the cons against, but I try to be honest.

Whatever the "ideal" state is, or whatever positives we can cook up, there are a number of severe negatives which we've demonstrated time and again we have no idea how to address at a global scale, where just winging it doesn't seem prudent:

- Much of the currently populated world will be under water. We have a hard enough time housing a few Syrian refugees and El Salvadorean asylum seekers. Where are we going to put all of Florida, the populated halves of Louisiana, Alabama, the Carolinas, Virigina, ...?

- The frequency and geographic diversity of wet-bulb events will increase substantially. If you're in the wrong place at the wrong time for too long and don't have A/C, you will die. Shade won't save you. Being indoors won't save you. Fans and swamp coolers won't fix it. Beyond the sea level rise, this will render vast swathes of land uninhabitable (like much of India).

- The frequency and intensity of severe weather events -- straight-line winds, tornados, hurricanes, ... -- will increase. We're expecting 20-40% more CAT4/CAT5 hurricanes by the year 2100. In the US, tornado alley will expand eastward. Much more importantly than all of that, the increased energy and humidity will make storms less predictable (harder to evacuate in time, much more devastating).

- The impact isn't limited to people. Our crops have been domesticated over hundreds to thousands of years, and GMOs can only do so much to address hardiness when growing soft balls of sugar and starch on a stem (also applies to corn and wheat, not just typical fruits and vegetables). The last thing you want with a growing population, with some of your best crop land being claimed by the ocean, with neighboring crop land being claimed by oceanic storms many years, with that growing population having less space to exist and encroaching inward toward the rest of your crops, is for crops to be harder to grow. Even if 4 years out of 5 are fine, an extra hot spell followed by an extra humid spell is all it takes to kill your tomatoes, eggplants, peppers, and potatoes (or make a huge dent in their yield that year). Other crops have other undesirable weather patterns. There's a chance this is controversial, but I'll posit that mass starvation (above and beyond the current levels of global starvation) every 5-10 years isn't a good outcome.

And so on. I haven't yet seen anyone try to argue that those negatives are good. Maybe it's a "China hoax" or whatever, but a nicer average climate in Canada (mind you, the extreme weather events will still make most months more unpleasant than the status quo -- averaging weather isn't usually useful) or whatever the proposed upside happens to be won't make up for the cons if the thing is real.

[0] https://xkcd.com/1732/

[1] https://xkcd.com/2500/